1. Field of the Invention
The present invention relates to an electrode plate manufacturing method and an electrode plate manufacturing apparatus. More specifically, the present invention relates to an electrode plate manufacturing method and an electrode plate manufacturing apparatus that manufactures an electrode plate such that a belt-shaped current collector foil is conveyed and an active material layer is formed in a part of the conveyed current collector foil in a width direction.
2. Description of Related Art
A battery such as a lithium-ion secondary battery is formed such that positive and negative electrode plates and an electrolyte are accommodated in a case. The positive and negative electrode plates each have a current collector foil and an active material layer. The active material layer contains at least an active material that contributes to charging and discharging, and a binding material that binds the active material onto the current collector foil so as to form the active material layer. A conventional technique related to a manufacturing method of such an electrode plate is disclosed in Japanese Patent Application Publication No. 2014-191880 (JP 2014-191880 A), for example.
JP 2014-191880 A discloses a technique in which a powder constituent containing an active material and so on is supplied to an opposed position of a pair of press rolls from above, and the powder constituent is pressed at the opposed position of the pair of press rolls so as to form an active material layer. Further, in JP 2014-191880 A, a current collector foil is caused to pass the opposed position of the pair of press rolls in a state where the current collector foil is wound around an outer peripheral surface of one of the press rolls. A method described herein is such that an active material layer is formed on a surface of the current collector foil at the opposed position of the pair of press rolls so as to manufacture an electrode plate.
In the meantime, an electrode plate may have a formation region where an active material layer is formed on a current collector foil, and a non-formation region where the current collector foil is exposed. In a device having a configuration of the above conventional technique, in order to manufacture an electrode plate while a formation region and a non-formation region are provided on a current collector foil in a width direction, a powder constituent should be supplied only to a part to become the formation region on the current collector foil. On this account, it is conceivable that a division plate is provided in a boundary between the formation region and the non-formation region so that the powder constituent is supplied only to a formation-region side, for example.
Further, it is preferable that the boundary between the formation region and the non-formation region in the electrode plate be formed in parallel to a conveying direction of the current collector foil. This is to manufacture the electrode plate with a high quality. Further, in order to form the boundary between the formation region and the non-formation region in parallel to the conveying direction of the current collector foil, the division plate should make contact with the current collector foil and the press roll. The reason is as follows: in a case where a gap is formed between the current collector foil or the press roll and the division plate, a powder constituent supplied to a part to become the formation region comes inside a part to become the non-formation region through the gap.
However, in a case where the division plate is provided so as to make contact with the current collector foil or the press roll, the current collector foil or the press roll may be damaged. In a case where the current collector foil or the press roll is damaged, it is difficult to manufacture an electrode plate with a high quality. That is, in the device having the configuration of the conventional technique, it is difficult to manufacture the electrode plate having the formation region and the non-formation region in the width direction while maintaining the high quality.